// SPDX-License-Identifier: GPL-2.0
/*
 * drivers/base/power/runtime.c - Helper functions for device runtime PM
 *
 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
 * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu>
 */
#include <generated/deconfig.h>
#include <linux/sched/mm.h>
#include <linux/ktime.h>
#include <linux/hrtimer.h>
#include <linux/export.h>
#include <linux/pm_runtime.h>
#include <linux/pm_wakeirq.h>
#include <trace/events/rpm.h>

#include "../base.h"
#include "power.h"

//typedef int (*pm_callback_t)(struct device *);

//static pm_callback_t __rpm_get_callback(struct device *dev, size_t cb_offset)
//{
//	pm_callback_t cb;
//	const struct dev_pm_ops *ops;

//	if (dev->pm_domain)
//		ops = &dev->pm_domain->ops;
//	else if (dev->type && dev->type->pm)
//		ops = dev->type->pm;
//	else if (dev->class && dev->class->pm)
//		ops = dev->class->pm;
//	else if (dev->bus && dev->bus->pm)
//		ops = dev->bus->pm;
//	else
//		ops = NULL;

//	if (ops)
//		cb = *(pm_callback_t *)((void *)ops + cb_offset);
//	else
//		cb = NULL;

//	if (!cb && dev->driver && dev->driver->pm)
//		cb = *(pm_callback_t *)((void *)dev->driver->pm + cb_offset);

//	return cb;
//}

//#define RPM_GET_CALLBACK(dev, callback) \
//		__rpm_get_callback(dev, offsetof(struct dev_pm_ops, callback))

//static int rpm_resume(struct device *dev, int rpmflags);
//static int rpm_suspend(struct device *dev, int rpmflags);

///**
// * update_pm_runtime_accounting - Update the time accounting of power states
// * @dev: Device to update the accounting for
// *
// * In order to be able to have time accounting of the various power states
// * (as used by programs such as PowerTOP to show the effectiveness of runtime
// * PM), we need to track the time spent in each state.
// * update_pm_runtime_accounting must be called each time before the
// * runtime_status field is updated, to account the time in the old state
// * correctly.
// */
//static void update_pm_runtime_accounting(struct device *dev)
//{
//	u64 now, last, delta;

//	if (dev->power.disable_depth > 0)
//		return;

//	last = dev->power.accounting_timestamp;

//	now = ktime_get_mono_fast_ns();
//	dev->power.accounting_timestamp = now;

//	/*
//	 * Because ktime_get_mono_fast_ns() is not monotonic during
//	 * timekeeping updates, ensure that 'now' is after the last saved
//	 * timesptamp.
//	 */
//	if (now < last)
//		return;

//	delta = now - last;

//	if (dev->power.runtime_status == RPM_SUSPENDED)
//		dev->power.suspended_time += delta;
//	else
//		dev->power.active_time += delta;
//}

//static void __update_runtime_status(struct device *dev, enum rpm_status status)
//{
//	update_pm_runtime_accounting(dev);
//	dev->power.runtime_status = status;
//}

//static u64 rpm_get_accounted_time(struct device *dev, bool suspended)
//{
//	u64 time;
//	unsigned long flags;

//	spin_lock_irqsave(&dev->power.lock, flags);

//	update_pm_runtime_accounting(dev);
//	time = suspended ? dev->power.suspended_time : dev->power.active_time;

//	spin_unlock_irqrestore(&dev->power.lock, flags);

//	return time;
//}

//u64 pm_runtime_active_time(struct device *dev)
//{
//	return rpm_get_accounted_time(dev, false);
//}

//u64 pm_runtime_suspended_time(struct device *dev)
//{
//	return rpm_get_accounted_time(dev, true);
//}
//EXPORT_SYMBOL_GPL(pm_runtime_suspended_time);

///**
// * pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
// * @dev: Device to handle.
// */
//static void pm_runtime_deactivate_timer(struct device *dev)
//{
//	if (dev->power.timer_expires > 0) {
//		hrtimer_try_to_cancel(&dev->power.suspend_timer);
//		dev->power.timer_expires = 0;
//	}
//}

///**
// * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests.
// * @dev: Device to handle.
// */
//static void pm_runtime_cancel_pending(struct device *dev)
//{
//	pm_runtime_deactivate_timer(dev);
//	/*
//	 * In case there's a request pending, make sure its work function will
//	 * return without doing anything.
//	 */
//	dev->power.request = RPM_REQ_NONE;
//}

///*
// * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time.
// * @dev: Device to handle.
// *
// * Compute the autosuspend-delay expiration time based on the device's
// * power.last_busy time.  If the delay has already expired or is disabled
// * (negative) or the power.use_autosuspend flag isn't set, return 0.
// * Otherwise return the expiration time in nanoseconds (adjusted to be nonzero).
// *
// * This function may be called either with or without dev->power.lock held.
// * Either way it can be racy, since power.last_busy may be updated at any time.
// */
//u64 pm_runtime_autosuspend_expiration(struct device *dev)
//{
//	int autosuspend_delay;
//	u64 expires;

//	if (!dev->power.use_autosuspend)
//		return 0;

//	autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay);
//	if (autosuspend_delay < 0)
//		return 0;

//	expires  = READ_ONCE(dev->power.last_busy);
//	expires += (u64)autosuspend_delay * NSEC_PER_MSEC;
//	if (expires > ktime_get_mono_fast_ns())
//		return expires;	/* Expires in the future */

//	return 0;
//}
//EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);

//static int dev_memalloc_noio(struct device *dev, void *data)
//{
//	return dev->power.memalloc_noio;
//}

///*
// * pm_runtime_set_memalloc_noio - Set a device's memalloc_noio flag.
// * @dev: Device to handle.
// * @enable: True for setting the flag and False for clearing the flag.
// *
// * Set the flag for all devices in the path from the device to the
// * root device in the device tree if @enable is true, otherwise clear
// * the flag for devices in the path whose siblings don't set the flag.
// *
// * The function should only be called by block device, or network
// * device driver for solving the deadlock problem during runtime
// * resume/suspend:
// *
// *     If memory allocation with GFP_KERNEL is called inside runtime
// *     resume/suspend callback of any one of its ancestors(or the
// *     block device itself), the deadlock may be triggered inside the
// *     memory allocation since it might not complete until the block
// *     device becomes active and the involed page I/O finishes. The
// *     situation is pointed out first by Alan Stern. Network device
// *     are involved in iSCSI kind of situation.
// *
// * The lock of dev_hotplug_mutex is held in the function for handling
// * hotplug race because pm_runtime_set_memalloc_noio() may be called
// * in async probe().
// *
// * The function should be called between device_add() and device_del()
// * on the affected device(block/network device).
// */
//void pm_runtime_set_memalloc_noio(struct device *dev, bool enable)
//{
//	static DEFINE_MUTEX(dev_hotplug_mutex);

//	mutex_lock(&dev_hotplug_mutex);
//	for (;;) {
//		bool enabled;

//		/* hold power lock since bitfield is not SMP-safe. */
//		spin_lock_irq(&dev->power.lock);
//		enabled = dev->power.memalloc_noio;
//		dev->power.memalloc_noio = enable;
//		spin_unlock_irq(&dev->power.lock);

//		/*
//		 * not need to enable ancestors any more if the device
//		 * has been enabled.
//		 */
//		if (enabled && enable)
//			break;

//		dev = dev->parent;

//		/*
//		 * clear flag of the parent device only if all the
//		 * children don't set the flag because ancestor's
//		 * flag was set by any one of the descendants.
//		 */
//		if (!dev || (!enable &&
//			     device_for_each_child(dev, NULL,
//						   dev_memalloc_noio)))
//			break;
//	}
//	mutex_unlock(&dev_hotplug_mutex);
//}
//EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio);

///**
// * rpm_check_suspend_allowed - Test whether a device may be suspended.
// * @dev: Device to test.
// */
//static int rpm_check_suspend_allowed(struct device *dev)
//{
//	int retval = 0;

//	if (dev->power.runtime_error)
//		retval = -EINVAL;
//	else if (dev->power.disable_depth > 0)
//		retval = -EACCES;
//	else if (atomic_read(&dev->power.usage_count) > 0)
//		retval = -EAGAIN;
//	else if (!dev->power.ignore_children &&
//			atomic_read(&dev->power.child_count))
//		retval = -EBUSY;

//	/* Pending resume requests take precedence over suspends. */
//	else if ((dev->power.deferred_resume
//			&& dev->power.runtime_status == RPM_SUSPENDING)
//	    || (dev->power.request_pending
//			&& dev->power.request == RPM_REQ_RESUME))
//		retval = -EAGAIN;
//	else if (__dev_pm_qos_resume_latency(dev) == 0)
//		retval = -EPERM;
//	else if (dev->power.runtime_status == RPM_SUSPENDED)
//		retval = 1;

//	return retval;
//}

//static int rpm_get_suppliers(struct device *dev)
//{
//	struct device_link *link;

//	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
//				device_links_read_lock_held()) {
//		int retval;

//		if (!(link->flags & DL_FLAG_PM_RUNTIME))
//			continue;

//		retval = pm_runtime_get_sync(link->supplier);
//		/* Ignore suppliers with disabled runtime PM. */
//		if (retval < 0 && retval != -EACCES) {
//			pm_runtime_put_noidle(link->supplier);
//			return retval;
//		}
//		refcount_inc(&link->rpm_active);
//	}
//	return 0;
//}

//static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend)
//{
//	struct device_link *link;

//	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
//				device_links_read_lock_held()) {

//		while (refcount_dec_not_one(&link->rpm_active))
//			pm_runtime_put_noidle(link->supplier);

//		if (try_to_suspend)
//			pm_request_idle(link->supplier);
//	}
//}

//static void rpm_put_suppliers(struct device *dev)
//{
//	__rpm_put_suppliers(dev, true);
//}

//static void rpm_suspend_suppliers(struct device *dev)
//{
//	struct device_link *link;
////	int idx = device_links_read_lock();

//	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
//				device_links_read_lock_held())
//		pm_request_idle(link->supplier);

////	device_links_read_unlock(idx);
//}

///**
// * __rpm_callback - Run a given runtime PM callback for a given device.
// * @cb: Runtime PM callback to run.
// * @dev: Device to run the callback for.
// */
//static int __rpm_callback(int (*cb)(struct device *), struct device *dev)
//	__releases(&dev->power.lock) __acquires(&dev->power.lock)
//{
//	int retval, idx;
//	bool use_links = dev->power.links_count > 0;

//	if (dev->power.irq_safe) {
//		spin_unlock(&dev->power.lock);
//	} else {
//		spin_unlock_irq(&dev->power.lock);

//		/*
//		 * Resume suppliers if necessary.
//		 *
//		 * The device's runtime PM status cannot change until this
//		 * routine returns, so it is safe to read the status outside of
//		 * the lock.
//		 */
//		if (use_links && dev->power.runtime_status == RPM_RESUMING) {
//			idx = device_links_read_lock();

//			retval = rpm_get_suppliers(dev);
//			if (retval) {
//				rpm_put_suppliers(dev);
//				goto fail;
//			}

//			device_links_read_unlock(idx);
//		}
//	}

//	retval = cb(dev);

//	if (dev->power.irq_safe) {
//		spin_lock(&dev->power.lock);
//	} else {
//		/*
//		 * If the device is suspending and the callback has returned
//		 * success, drop the usage counters of the suppliers that have
//		 * been reference counted on its resume.
//		 *
//		 * Do that if resume fails too.
//		 */
//		if (use_links
//		    && ((dev->power.runtime_status == RPM_SUSPENDING && !retval)
//		    || (dev->power.runtime_status == RPM_RESUMING && retval))) {
//			idx = device_links_read_lock();

//			__rpm_put_suppliers(dev, false);

//fail:
//			device_links_read_unlock(idx);
//		}

//		spin_lock_irq(&dev->power.lock);
//	}

//	return retval;
//}

///**
// * rpm_idle - Notify device bus type if the device can be suspended.
// * @dev: Device to notify the bus type about.
// * @rpmflags: Flag bits.
// *
// * Check if the device's runtime PM status allows it to be suspended.  If
// * another idle notification has been started earlier, return immediately.  If
// * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
// * run the ->runtime_idle() callback directly. If the ->runtime_idle callback
// * doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag.
// *
// * This function must be called under dev->power.lock with interrupts disabled.
// */
//static int rpm_idle(struct device *dev, int rpmflags)
//{
//	int (*callback)(struct device *);
//	int retval;

//	trace_rpm_idle_rcuidle(dev, rpmflags);
//	retval = rpm_check_suspend_allowed(dev);
//	if (retval < 0)
//		;	/* Conditions are wrong. */

//	/* Idle notifications are allowed only in the RPM_ACTIVE state. */
//	else if (dev->power.runtime_status != RPM_ACTIVE)
//		retval = -EAGAIN;

//	/*
//	 * Any pending request other than an idle notification takes
//	 * precedence over us, except that the timer may be running.
//	 */
//	else if (dev->power.request_pending &&
//	    dev->power.request > RPM_REQ_IDLE)
//		retval = -EAGAIN;

//	/* Act as though RPM_NOWAIT is always set. */
//	else if (dev->power.idle_notification)
//		retval = -EINPROGRESS;
//	if (retval)
//		goto out;

//	/* Pending requests need to be canceled. */
//	dev->power.request = RPM_REQ_NONE;

//	if (dev->power.no_callbacks)
//		goto out;

//	/* Carry out an asynchronous or a synchronous idle notification. */
//	if (rpmflags & RPM_ASYNC) {
//		dev->power.request = RPM_REQ_IDLE;
//		if (!dev->power.request_pending) {
//			dev->power.request_pending = true;
//			queue_work(pm_wq, &dev->power.work);
//		}
//		trace_rpm_return_int_rcuidle(dev, _THIS_IP_, 0);
//		return 0;
//	}

//	dev->power.idle_notification = true;

//	callback = RPM_GET_CALLBACK(dev, runtime_idle);

//	if (callback)
//		retval = __rpm_callback(callback, dev);

//	dev->power.idle_notification = false;
//	wake_up_all(&dev->power.wait_queue);

// out:
//	trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
//	return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO);
//}

///**
// * rpm_callback - Run a given runtime PM callback for a given device.
// * @cb: Runtime PM callback to run.
// * @dev: Device to run the callback for.
// */
//static int rpm_callback(int (*cb)(struct device *), struct device *dev)
//{
//	int retval;

//	if (!cb)
//		return -ENOSYS;

//	if (dev->power.memalloc_noio) {
//		unsigned int noio_flag;

//		/*
//		 * Deadlock might be caused if memory allocation with
//		 * GFP_KERNEL happens inside runtime_suspend and
//		 * runtime_resume callbacks of one block device's
//		 * ancestor or the block device itself. Network
//		 * device might be thought as part of iSCSI block
//		 * device, so network device and its ancestor should
//		 * be marked as memalloc_noio too.
//		 */
//		noio_flag = memalloc_noio_save();
//		retval = __rpm_callback(cb, dev);
//		memalloc_noio_restore(noio_flag);
//	} else {
//		retval = __rpm_callback(cb, dev);
//	}

//	dev->power.runtime_error = retval;
//	return retval != -EACCES ? retval : -EIO;
//}

///**
// * rpm_suspend - Carry out runtime suspend of given device.
// * @dev: Device to suspend.
// * @rpmflags: Flag bits.
// *
// * Check if the device's runtime PM status allows it to be suspended.
// * Cancel a pending idle notification, autosuspend or suspend. If
// * another suspend has been started earlier, either return immediately
// * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC
// * flags. If the RPM_ASYNC flag is set then queue a suspend request;
// * otherwise run the ->runtime_suspend() callback directly. When
// * ->runtime_suspend succeeded, if a deferred resume was requested while
// * the callback was running then carry it out, otherwise send an idle
// * notification for its parent (if the suspend succeeded and both
// * ignore_children of parent->power and irq_safe of dev->power are not set).
// * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO
// * flag is set and the next autosuspend-delay expiration time is in the
// * future, schedule another autosuspend attempt.
// *
// * This function must be called under dev->power.lock with interrupts disabled.
// */
//static int rpm_suspend(struct device *dev, int rpmflags)
//	__releases(&dev->power.lock) __acquires(&dev->power.lock)
//{
//	int (*callback)(struct device *);
//	struct device *parent = NULL;
//	int retval;

//	trace_rpm_suspend_rcuidle(dev, rpmflags);

// repeat:
//	retval = rpm_check_suspend_allowed(dev);
//	if (retval < 0)
//		goto out;	/* Conditions are wrong. */

//	/* Synchronous suspends are not allowed in the RPM_RESUMING state. */
//	if (dev->power.runtime_status == RPM_RESUMING && !(rpmflags & RPM_ASYNC))
//		retval = -EAGAIN;
//	if (retval)
//		goto out;

//	/* If the autosuspend_delay time hasn't expired yet, reschedule. */
//	if ((rpmflags & RPM_AUTO)
//	    && dev->power.runtime_status != RPM_SUSPENDING) {
//		u64 expires = pm_runtime_autosuspend_expiration(dev);

//		if (expires != 0) {
//			/* Pending requests need to be canceled. */
//			dev->power.request = RPM_REQ_NONE;

//			/*
//			 * Optimization: If the timer is already running and is
//			 * set to expire at or before the autosuspend delay,
//			 * avoid the overhead of resetting it.  Just let it
//			 * expire; pm_suspend_timer_fn() will take care of the
//			 * rest.
//			 */
//			if (!(dev->power.timer_expires &&
//					dev->power.timer_expires <= expires)) {
//				/*
//				 * We add a slack of 25% to gather wakeups
//				 * without sacrificing the granularity.
//				 */
//				u64 slack = (u64)READ_ONCE(dev->power.autosuspend_delay) *
//						    (NSEC_PER_MSEC >> 2);

//				dev->power.timer_expires = expires;
//				hrtimer_start_range_ns(&dev->power.suspend_timer,
//						ns_to_ktime(expires),
//						slack,
//						HRTIMER_MODE_ABS);
//			}
//			dev->power.timer_autosuspends = 1;
//			goto out;
//		}
//	}

//	/* Other scheduled or pending requests need to be canceled. */
//	pm_runtime_cancel_pending(dev);

//	if (dev->power.runtime_status == RPM_SUSPENDING) {
//		DEFINE_WAIT(wait);

//		if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
//			retval = -EINPROGRESS;
//			goto out;
//		}

//		if (dev->power.irq_safe) {
//			spin_unlock(&dev->power.lock);

//			cpu_relax();

//			spin_lock(&dev->power.lock);
//			goto repeat;
//		}

//		/* Wait for the other suspend running in parallel with us. */
//		for (;;) {
//			prepare_to_wait(&dev->power.wait_queue, &wait,
//					TASK_UNINTERRUPTIBLE);
//			if (dev->power.runtime_status != RPM_SUSPENDING)
//				break;

//			spin_unlock_irq(&dev->power.lock);

//			schedule();

//			spin_lock_irq(&dev->power.lock);
//		}
//		finish_wait(&dev->power.wait_queue, &wait);
//		goto repeat;
//	}

//	if (dev->power.no_callbacks)
//		goto no_callback;	/* Assume success. */

//	/* Carry out an asynchronous or a synchronous suspend. */
//	if (rpmflags & RPM_ASYNC) {
//		dev->power.request = (rpmflags & RPM_AUTO) ?
//		    RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
//		if (!dev->power.request_pending) {
//			dev->power.request_pending = true;
//			queue_work(pm_wq, &dev->power.work);
//		}
//		goto out;
//	}

//	__update_runtime_status(dev, RPM_SUSPENDING);

//	callback = RPM_GET_CALLBACK(dev, runtime_suspend);

//	dev_pm_enable_wake_irq_check(dev, true);
//	retval = rpm_callback(callback, dev);
//	if (retval)
//		goto fail;

// no_callback:
//	__update_runtime_status(dev, RPM_SUSPENDED);
//	pm_runtime_deactivate_timer(dev);

//	if (dev->parent) {
//		parent = dev->parent;
//		atomic_add_unless(&parent->power.child_count, -1, 0);
//	}
//	wake_up_all(&dev->power.wait_queue);

//	if (dev->power.deferred_resume) {
//		dev->power.deferred_resume = false;
//		rpm_resume(dev, 0);
//		retval = -EAGAIN;
//		goto out;
//	}

//	if (dev->power.irq_safe)
//		goto out;

//	/* Maybe the parent is now able to suspend. */
//	if (parent && !parent->power.ignore_children) {
//		spin_unlock(&dev->power.lock);

//		spin_lock(&parent->power.lock);
//		rpm_idle(parent, RPM_ASYNC);
//		spin_unlock(&parent->power.lock);

//		spin_lock(&dev->power.lock);
//	}
//	/* Maybe the suppliers are now able to suspend. */
//	if (dev->power.links_count > 0) {
//		spin_unlock_irq(&dev->power.lock);

//		rpm_suspend_suppliers(dev);

//		spin_lock_irq(&dev->power.lock);
//	}

// out:
//	trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);

//	return retval;

// fail:
//	dev_pm_disable_wake_irq_check(dev);
//	__update_runtime_status(dev, RPM_ACTIVE);
//	dev->power.deferred_resume = false;
//	wake_up_all(&dev->power.wait_queue);

//	if (retval == -EAGAIN || retval == -EBUSY) {
//		dev->power.runtime_error = 0;

//		/*
//		 * If the callback routine failed an autosuspend, and
//		 * if the last_busy time has been updated so that there
//		 * is a new autosuspend expiration time, automatically
//		 * reschedule another autosuspend.
//		 */
//		if ((rpmflags & RPM_AUTO) &&
//		    pm_runtime_autosuspend_expiration(dev) != 0)
//			goto repeat;
//	} else {
//		pm_runtime_cancel_pending(dev);
//	}
//	goto out;
//}

///**
// * rpm_resume - Carry out runtime resume of given device.
// * @dev: Device to resume.
// * @rpmflags: Flag bits.
// *
// * Check if the device's runtime PM status allows it to be resumed.  Cancel
// * any scheduled or pending requests.  If another resume has been started
// * earlier, either return immediately or wait for it to finish, depending on the
// * RPM_NOWAIT and RPM_ASYNC flags.  Similarly, if there's a suspend running in
// * parallel with this function, either tell the other process to resume after
// * suspending (deferred_resume) or wait for it to finish.  If the RPM_ASYNC
// * flag is set then queue a resume request; otherwise run the
// * ->runtime_resume() callback directly.  Queue an idle notification for the
// * device if the resume succeeded.
// *
// * This function must be called under dev->power.lock with interrupts disabled.
// */
//static int rpm_resume(struct device *dev, int rpmflags)
//	__releases(&dev->power.lock) __acquires(&dev->power.lock)
//{
//	int (*callback)(struct device *);
//	struct device *parent = NULL;
//	int retval = 0;

//	trace_rpm_resume_rcuidle(dev, rpmflags);

// repeat:
//	if (dev->power.runtime_error)
//		retval = -EINVAL;
//	else if (dev->power.disable_depth == 1 && dev->power.is_suspended
//	    && dev->power.runtime_status == RPM_ACTIVE)
//		retval = 1;
//	else if (dev->power.disable_depth > 0)
//		retval = -EACCES;
//	if (retval)
//		goto out;

//	/*
//	 * Other scheduled or pending requests need to be canceled.  Small
//	 * optimization: If an autosuspend timer is running, leave it running
//	 * rather than cancelling it now only to restart it again in the near
//	 * future.
//	 */
//	dev->power.request = RPM_REQ_NONE;
//	if (!dev->power.timer_autosuspends)
//		pm_runtime_deactivate_timer(dev);

//	if (dev->power.runtime_status == RPM_ACTIVE) {
//		retval = 1;
//		goto out;
//	}

//	if (dev->power.runtime_status == RPM_RESUMING
//	    || dev->power.runtime_status == RPM_SUSPENDING) {
//		DEFINE_WAIT(wait);

//		if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
//			if (dev->power.runtime_status == RPM_SUSPENDING)
//				dev->power.deferred_resume = true;
//			else
//				retval = -EINPROGRESS;
//			goto out;
//		}

//		if (dev->power.irq_safe) {
//			spin_unlock(&dev->power.lock);

//			cpu_relax();

//			spin_lock(&dev->power.lock);
//			goto repeat;
//		}

//		/* Wait for the operation carried out in parallel with us. */
//		for (;;) {
//			prepare_to_wait(&dev->power.wait_queue, &wait,
//					TASK_UNINTERRUPTIBLE);
//			if (dev->power.runtime_status != RPM_RESUMING
//			    && dev->power.runtime_status != RPM_SUSPENDING)
//				break;

//			spin_unlock_irq(&dev->power.lock);

//			schedule();

//			spin_lock_irq(&dev->power.lock);
//		}
//		finish_wait(&dev->power.wait_queue, &wait);
//		goto repeat;
//	}

//	/*
//	 * See if we can skip waking up the parent.  This is safe only if
//	 * power.no_callbacks is set, because otherwise we don't know whether
//	 * the resume will actually succeed.
//	 */
//	if (dev->power.no_callbacks && !parent && dev->parent) {
//		spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING);
//		if (dev->parent->power.disable_depth > 0
//		    || dev->parent->power.ignore_children
//		    || dev->parent->power.runtime_status == RPM_ACTIVE) {
//			atomic_inc(&dev->parent->power.child_count);
//			spin_unlock(&dev->parent->power.lock);
//			retval = 1;
//			goto no_callback;	/* Assume success. */
//		}
//		spin_unlock(&dev->parent->power.lock);
//	}

//	/* Carry out an asynchronous or a synchronous resume. */
//	if (rpmflags & RPM_ASYNC) {
//		dev->power.request = RPM_REQ_RESUME;
//		if (!dev->power.request_pending) {
//			dev->power.request_pending = true;
//			queue_work(pm_wq, &dev->power.work);
//		}
//		retval = 0;
//		goto out;
//	}

//	if (!parent && dev->parent) {
//		/*
//		 * Increment the parent's usage counter and resume it if
//		 * necessary.  Not needed if dev is irq-safe; then the
//		 * parent is permanently resumed.
//		 */
//		parent = dev->parent;
//		if (dev->power.irq_safe)
//			goto skip_parent;
//		spin_unlock(&dev->power.lock);

//		pm_runtime_get_noresume(parent);

//		spin_lock(&parent->power.lock);
//		/*
//		 * Resume the parent if it has runtime PM enabled and not been
//		 * set to ignore its children.
//		 */
//		if (!parent->power.disable_depth
//		    && !parent->power.ignore_children) {
//			rpm_resume(parent, 0);
//			if (parent->power.runtime_status != RPM_ACTIVE)
//				retval = -EBUSY;
//		}
//		spin_unlock(&parent->power.lock);

//		spin_lock(&dev->power.lock);
//		if (retval)
//			goto out;
//		goto repeat;
//	}
// skip_parent:

//	if (dev->power.no_callbacks)
//		goto no_callback;	/* Assume success. */

//	__update_runtime_status(dev, RPM_RESUMING);

//	callback = RPM_GET_CALLBACK(dev, runtime_resume);

//	dev_pm_disable_wake_irq_check(dev);
//	retval = rpm_callback(callback, dev);
//	if (retval) {
//		__update_runtime_status(dev, RPM_SUSPENDED);
//		pm_runtime_cancel_pending(dev);
//		dev_pm_enable_wake_irq_check(dev, false);
//	} else {
// no_callback:
//		__update_runtime_status(dev, RPM_ACTIVE);
//		pm_runtime_mark_last_busy(dev);
//		if (parent)
//			atomic_inc(&parent->power.child_count);
//	}
//	wake_up_all(&dev->power.wait_queue);

//	if (retval >= 0)
//		rpm_idle(dev, RPM_ASYNC);

// out:
//	if (parent && !dev->power.irq_safe) {
//		spin_unlock_irq(&dev->power.lock);

//		pm_runtime_put(parent);

//		spin_lock_irq(&dev->power.lock);
//	}

//	trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);

//	return retval;
//}

///**
// * pm_runtime_work - Universal runtime PM work function.
// * @work: Work structure used for scheduling the execution of this function.
// *
// * Use @work to get the device object the work is to be done for, determine what
// * is to be done and execute the appropriate runtime PM function.
// */
//static void pm_runtime_work(struct work_struct *work)
//{
//	struct device *dev = container_of(work, struct device, power.work);
//	enum rpm_request req;

//	spin_lock_irq(&dev->power.lock);

//	if (!dev->power.request_pending)
//		goto out;

//	req = dev->power.request;
//	dev->power.request = RPM_REQ_NONE;
//	dev->power.request_pending = false;

//	switch (req) {
//	case RPM_REQ_NONE:
//		break;
//	case RPM_REQ_IDLE:
//		rpm_idle(dev, RPM_NOWAIT);
//		break;
//	case RPM_REQ_SUSPEND:
//		rpm_suspend(dev, RPM_NOWAIT);
//		break;
//	case RPM_REQ_AUTOSUSPEND:
//		rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
//		break;
//	case RPM_REQ_RESUME:
//		rpm_resume(dev, RPM_NOWAIT);
//		break;
//	}

// out:
//	spin_unlock_irq(&dev->power.lock);
//}

///**
// * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
// * @data: Device pointer passed by pm_schedule_suspend().
// *
// * Check if the time is right and queue a suspend request.
// */
//static enum hrtimer_restart  pm_suspend_timer_fn(struct hrtimer *timer)
//{
//	struct device *dev = container_of(timer, struct device, power.suspend_timer);
//	unsigned long flags;
//	u64 expires;

//	spin_lock_irqsave(&dev->power.lock, flags);

//	expires = dev->power.timer_expires;
//	/*
//	 * If 'expires' is after the current time, we've been called
//	 * too early.
//	 */
//	if (expires > 0 && expires < ktime_get_mono_fast_ns()) {
//		dev->power.timer_expires = 0;
//		rpm_suspend(dev, dev->power.timer_autosuspends ?
//		    (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
//	}

//	spin_unlock_irqrestore(&dev->power.lock, flags);

//	return HRTIMER_NORESTART;
//}

///**
// * pm_schedule_suspend - Set up a timer to submit a suspend request in future.
// * @dev: Device to suspend.
// * @delay: Time to wait before submitting a suspend request, in milliseconds.
// */
//int pm_schedule_suspend(struct device *dev, unsigned int delay)
//{
//	unsigned long flags;
//	u64 expires;
//	int retval;

//	spin_lock_irqsave(&dev->power.lock, flags);

//	if (!delay) {
//		retval = rpm_suspend(dev, RPM_ASYNC);
//		goto out;
//	}

//	retval = rpm_check_suspend_allowed(dev);
//	if (retval)
//		goto out;

//	/* Other scheduled or pending requests need to be canceled. */
//	pm_runtime_cancel_pending(dev);

//	expires = ktime_get_mono_fast_ns() + (u64)delay * NSEC_PER_MSEC;
//	dev->power.timer_expires = expires;
//	dev->power.timer_autosuspends = 0;
//	hrtimer_start(&dev->power.suspend_timer, expires, HRTIMER_MODE_ABS);

// out:
//	spin_unlock_irqrestore(&dev->power.lock, flags);

//	return retval;
//}
//EXPORT_SYMBOL_GPL(pm_schedule_suspend);

/**
 * __pm_runtime_idle - Entry point for runtime idle operations.
 * @dev: Device to send idle notification for.
 * @rpmflags: Flag bits.
 *
 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
 * return immediately if it is larger than zero.  Then carry out an idle
 * notification, either synchronous or asynchronous.
 *
 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
 * or if pm_runtime_irq_safe() has been called.
 */
int __pm_runtime_idle(struct device *dev, int rpmflags)
{
//	unsigned long flags;
//	int retval;

//	if (rpmflags & RPM_GET_PUT) {
//		if (!atomic_dec_and_test(&dev->power.usage_count)) {
//			trace_rpm_usage_rcuidle(dev, rpmflags);
//			return 0;
//		}
//	}

//	might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);

//	spin_lock_irqsave(&dev->power.lock, flags);
//	retval = rpm_idle(dev, rpmflags);
//	spin_unlock_irqrestore(&dev->power.lock, flags);

//	return retval;
    return 0;
}
EXPORT_SYMBOL_GPL(__pm_runtime_idle);

/**
 * __pm_runtime_suspend - Entry point for runtime put/suspend operations.
 * @dev: Device to suspend.
 * @rpmflags: Flag bits.
 *
 * If the RPM_GET_PUT flag is set, decrement the device's usage count and
 * return immediately if it is larger than zero.  Then carry out a suspend,
 * either synchronous or asynchronous.
 *
 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
 * or if pm_runtime_irq_safe() has been called.
 */
int __pm_runtime_suspend(struct device *dev, int rpmflags)
{
//	unsigned long flags;
//	int retval;

//	if (rpmflags & RPM_GET_PUT) {
//		if (!atomic_dec_and_test(&dev->power.usage_count)) {
//			trace_rpm_usage_rcuidle(dev, rpmflags);
//			return 0;
//		}
//	}

//	might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);

//	spin_lock_irqsave(&dev->power.lock, flags);
//	retval = rpm_suspend(dev, rpmflags);
//	spin_unlock_irqrestore(&dev->power.lock, flags);

//	return retval;
    return 0;
}
EXPORT_SYMBOL_GPL(__pm_runtime_suspend);

/**
 * __pm_runtime_resume - Entry point for runtime resume operations.
 * @dev: Device to resume.
 * @rpmflags: Flag bits.
 *
 * If the RPM_GET_PUT flag is set, increment the device's usage count.  Then
 * carry out a resume, either synchronous or asynchronous.
 *
 * This routine may be called in atomic context if the RPM_ASYNC flag is set,
 * or if pm_runtime_irq_safe() has been called.
 */
int __pm_runtime_resume(struct device *dev, int rpmflags)
{
//	unsigned long flags;
//	int retval;

//	might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe &&
//			dev->power.runtime_status != RPM_ACTIVE);

//	if (rpmflags & RPM_GET_PUT)
//		atomic_inc(&dev->power.usage_count);

//	spin_lock_irqsave(&dev->power.lock, flags);
//	retval = rpm_resume(dev, rpmflags);
//	spin_unlock_irqrestore(&dev->power.lock, flags);

//	return retval;
    return 0;
}
EXPORT_SYMBOL_GPL(__pm_runtime_resume);

///**
// * pm_runtime_get_if_active - Conditionally bump up device usage counter.
// * @dev: Device to handle.
// * @ign_usage_count: Whether or not to look at the current usage counter value.
// *
// * Return -EINVAL if runtime PM is disabled for @dev.
// *
// * Otherwise, if the runtime PM status of @dev is %RPM_ACTIVE and either
// * @ign_usage_count is %true or the runtime PM usage counter of @dev is not
// * zero, increment the usage counter of @dev and return 1. Otherwise, return 0
// * without changing the usage counter.
// *
// * If @ign_usage_count is %true, this function can be used to prevent suspending
// * the device when its runtime PM status is %RPM_ACTIVE.
// *
// * If @ign_usage_count is %false, this function can be used to prevent
// * suspending the device when both its runtime PM status is %RPM_ACTIVE and its
// * runtime PM usage counter is not zero.
// *
// * The caller is resposible for decrementing the runtime PM usage counter of
// * @dev after this function has returned a positive value for it.
// */
//int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count)
//{
//	unsigned long flags;
//	int retval;

//	spin_lock_irqsave(&dev->power.lock, flags);
//	if (dev->power.disable_depth > 0) {
//		retval = -EINVAL;
//	} else if (dev->power.runtime_status != RPM_ACTIVE) {
//		retval = 0;
//	} else if (ign_usage_count) {
//		retval = 1;
//		atomic_inc(&dev->power.usage_count);
//	} else {
//		retval = atomic_inc_not_zero(&dev->power.usage_count);
//	}
//	trace_rpm_usage_rcuidle(dev, 0);
//	spin_unlock_irqrestore(&dev->power.lock, flags);

//	return retval;
//}
//EXPORT_SYMBOL_GPL(pm_runtime_get_if_active);

///**
// * __pm_runtime_set_status - Set runtime PM status of a device.
// * @dev: Device to handle.
// * @status: New runtime PM status of the device.
// *
// * If runtime PM of the device is disabled or its power.runtime_error field is
// * different from zero, the status may be changed either to RPM_ACTIVE, or to
// * RPM_SUSPENDED, as long as that reflects the actual state of the device.
// * However, if the device has a parent and the parent is not active, and the
// * parent's power.ignore_children flag is unset, the device's status cannot be
// * set to RPM_ACTIVE, so -EBUSY is returned in that case.
// *
// * If successful, __pm_runtime_set_status() clears the power.runtime_error field
// * and the device parent's counter of unsuspended children is modified to
// * reflect the new status.  If the new status is RPM_SUSPENDED, an idle
// * notification request for the parent is submitted.
// *
// * If @dev has any suppliers (as reflected by device links to them), and @status
// * is RPM_ACTIVE, they will be activated upfront and if the activation of one
// * of them fails, the status of @dev will be changed to RPM_SUSPENDED (instead
// * of the @status value) and the suppliers will be deacticated on exit.  The
// * error returned by the failing supplier activation will be returned in that
// * case.
// */
//int __pm_runtime_set_status(struct device *dev, unsigned int status)
//{
//	struct device *parent = dev->parent;
//	bool notify_parent = false;
//	int error = 0;

//	if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
//		return -EINVAL;

//	spin_lock_irq(&dev->power.lock);

//	/*
//	 * Prevent PM-runtime from being enabled for the device or return an
//	 * error if it is enabled already and working.
//	 */
//	if (dev->power.runtime_error || dev->power.disable_depth)
//		dev->power.disable_depth++;
//	else
//		error = -EAGAIN;

//	spin_unlock_irq(&dev->power.lock);

//	if (error)
//		return error;

//	/*
//	 * If the new status is RPM_ACTIVE, the suppliers can be activated
//	 * upfront regardless of the current status, because next time
//	 * rpm_put_suppliers() runs, the rpm_active refcounts of the links
//	 * involved will be dropped down to one anyway.
//	 */
//	if (status == RPM_ACTIVE) {
//		int idx = device_links_read_lock();

//		error = rpm_get_suppliers(dev);
//		if (error)
//			status = RPM_SUSPENDED;

//		device_links_read_unlock(idx);
//	}

//	spin_lock_irq(&dev->power.lock);

//	if (dev->power.runtime_status == status || !parent)
//		goto out_set;

//	if (status == RPM_SUSPENDED) {
//		atomic_add_unless(&parent->power.child_count, -1, 0);
//		notify_parent = !parent->power.ignore_children;
//	} else {
//		spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);

//		/*
//		 * It is invalid to put an active child under a parent that is
//		 * not active, has runtime PM enabled and the
//		 * 'power.ignore_children' flag unset.
//		 */
//		if (!parent->power.disable_depth
//		    && !parent->power.ignore_children
//		    && parent->power.runtime_status != RPM_ACTIVE) {
//			dev_err(dev, "runtime PM trying to activate child device %s but parent (%s) is not active\n",
//				dev_name(dev),
//				dev_name(parent));
//			error = -EBUSY;
//		} else if (dev->power.runtime_status == RPM_SUSPENDED) {
//			atomic_inc(&parent->power.child_count);
//		}

//		spin_unlock(&parent->power.lock);

//		if (error) {
//			status = RPM_SUSPENDED;
//			goto out;
//		}
//	}

// out_set:
//	__update_runtime_status(dev, status);
//	if (!error)
//		dev->power.runtime_error = 0;

// out:
//	spin_unlock_irq(&dev->power.lock);

//	if (notify_parent)
//		pm_request_idle(parent);

//	if (status == RPM_SUSPENDED) {
//		int idx = device_links_read_lock();

//		rpm_put_suppliers(dev);

//		device_links_read_unlock(idx);
//	}

//	pm_runtime_enable(dev);

//	return error;
//}
//EXPORT_SYMBOL_GPL(__pm_runtime_set_status);

///**
// * __pm_runtime_barrier - Cancel pending requests and wait for completions.
// * @dev: Device to handle.
// *
// * Flush all pending requests for the device from pm_wq and wait for all
// * runtime PM operations involving the device in progress to complete.
// *
// * Should be called under dev->power.lock with interrupts disabled.
// */
//static void __pm_runtime_barrier(struct device *dev)
//{
//	pm_runtime_deactivate_timer(dev);

//	if (dev->power.request_pending) {
//		dev->power.request = RPM_REQ_NONE;
//		spin_unlock_irq(&dev->power.lock);

//		cancel_work_sync(&dev->power.work);

//		spin_lock_irq(&dev->power.lock);
//		dev->power.request_pending = false;
//	}

//	if (dev->power.runtime_status == RPM_SUSPENDING
//	    || dev->power.runtime_status == RPM_RESUMING
//	    || dev->power.idle_notification) {
//		DEFINE_WAIT(wait);

//		/* Suspend, wake-up or idle notification in progress. */
//		for (;;) {
//			prepare_to_wait(&dev->power.wait_queue, &wait,
//					TASK_UNINTERRUPTIBLE);
//			if (dev->power.runtime_status != RPM_SUSPENDING
//			    && dev->power.runtime_status != RPM_RESUMING
//			    && !dev->power.idle_notification)
//				break;
//			spin_unlock_irq(&dev->power.lock);

//			schedule();

//			spin_lock_irq(&dev->power.lock);
//		}
//		finish_wait(&dev->power.wait_queue, &wait);
//	}
//}

/**
 * pm_runtime_barrier - Flush pending requests and wait for completions.
 * @dev: Device to handle.
 *
 * Prevent the device from being suspended by incrementing its usage counter and
 * if there's a pending resume request for the device, wake the device up.
 * Next, make sure that all pending requests for the device have been flushed
 * from pm_wq and wait for all runtime PM operations involving the device in
 * progress to complete.
 *
 * Return value:
 * 1, if there was a resume request pending and the device had to be woken up,
 * 0, otherwise
 */
int pm_runtime_barrier(struct device *dev)
{
	int retval = 0;

//	pm_runtime_get_noresume(dev);
//	spin_lock_irq(&dev->power.lock);

//	if (dev->power.request_pending
//	    && dev->power.request == RPM_REQ_RESUME) {
//		rpm_resume(dev, 0);
//		retval = 1;
//	}

//	__pm_runtime_barrier(dev);

//	spin_unlock_irq(&dev->power.lock);
//	pm_runtime_put_noidle(dev);

	return retval;
}
EXPORT_SYMBOL_GPL(pm_runtime_barrier);

///**
// * __pm_runtime_disable - Disable runtime PM of a device.
// * @dev: Device to handle.
// * @check_resume: If set, check if there's a resume request for the device.
// *
// * Increment power.disable_depth for the device and if it was zero previously,
// * cancel all pending runtime PM requests for the device and wait for all
// * operations in progress to complete.  The device can be either active or
// * suspended after its runtime PM has been disabled.
// *
// * If @check_resume is set and there's a resume request pending when
// * __pm_runtime_disable() is called and power.disable_depth is zero, the
// * function will wake up the device before disabling its runtime PM.
// */
//void __pm_runtime_disable(struct device *dev, bool check_resume)
//{
//	spin_lock_irq(&dev->power.lock);

//	if (dev->power.disable_depth > 0) {
//		dev->power.disable_depth++;
//		goto out;
//	}

//	/*
//	 * Wake up the device if there's a resume request pending, because that
//	 * means there probably is some I/O to process and disabling runtime PM
//	 * shouldn't prevent the device from processing the I/O.
//	 */
//	if (check_resume && dev->power.request_pending
//	    && dev->power.request == RPM_REQ_RESUME) {
//		/*
//		 * Prevent suspends and idle notifications from being carried
//		 * out after we have woken up the device.
//		 */
//		pm_runtime_get_noresume(dev);

//		rpm_resume(dev, 0);

//		pm_runtime_put_noidle(dev);
//	}

//	/* Update time accounting before disabling PM-runtime. */
//	update_pm_runtime_accounting(dev);

//	if (!dev->power.disable_depth++)
//		__pm_runtime_barrier(dev);

// out:
//	spin_unlock_irq(&dev->power.lock);
//}
//EXPORT_SYMBOL_GPL(__pm_runtime_disable);

///**
// * pm_runtime_enable - Enable runtime PM of a device.
// * @dev: Device to handle.
// */
//void pm_runtime_enable(struct device *dev)
//{
//	unsigned long flags;

//	spin_lock_irqsave(&dev->power.lock, flags);

//	if (dev->power.disable_depth > 0) {
//		dev->power.disable_depth--;

//		/* About to enable runtime pm, set accounting_timestamp to now */
//		if (!dev->power.disable_depth)
//			dev->power.accounting_timestamp = ktime_get_mono_fast_ns();
//	} else {
//		dev_warn(dev, "Unbalanced %s!\n", __func__);
//	}

//	WARN(!dev->power.disable_depth &&
//	     dev->power.runtime_status == RPM_SUSPENDED &&
//	     !dev->power.ignore_children &&
//	     atomic_read(&dev->power.child_count) > 0,
//	     "Enabling runtime PM for inactive device (%s) with active children\n",
//	     dev_name(dev));

//	spin_unlock_irqrestore(&dev->power.lock, flags);
//}
//EXPORT_SYMBOL_GPL(pm_runtime_enable);

///**
// * pm_runtime_forbid - Block runtime PM of a device.
// * @dev: Device to handle.
// *
// * Increase the device's usage count and clear its power.runtime_auto flag,
// * so that it cannot be suspended at run time until pm_runtime_allow() is called
// * for it.
// */
//void pm_runtime_forbid(struct device *dev)
//{
//	spin_lock_irq(&dev->power.lock);
//	if (!dev->power.runtime_auto)
//		goto out;

//	dev->power.runtime_auto = false;
//	atomic_inc(&dev->power.usage_count);
//	rpm_resume(dev, 0);

// out:
//	spin_unlock_irq(&dev->power.lock);
//}
//EXPORT_SYMBOL_GPL(pm_runtime_forbid);

///**
// * pm_runtime_allow - Unblock runtime PM of a device.
// * @dev: Device to handle.
// *
// * Decrease the device's usage count and set its power.runtime_auto flag.
// */
//void pm_runtime_allow(struct device *dev)
//{
//	spin_lock_irq(&dev->power.lock);
//	if (dev->power.runtime_auto)
//		goto out;

//	dev->power.runtime_auto = true;
//	if (atomic_dec_and_test(&dev->power.usage_count))
//		rpm_idle(dev, RPM_AUTO | RPM_ASYNC);
//	else
//		trace_rpm_usage_rcuidle(dev, RPM_AUTO | RPM_ASYNC);

// out:
//	spin_unlock_irq(&dev->power.lock);
//}
//EXPORT_SYMBOL_GPL(pm_runtime_allow);

///**
// * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device.
// * @dev: Device to handle.
// *
// * Set the power.no_callbacks flag, which tells the PM core that this
// * device is power-managed through its parent and has no runtime PM
// * callbacks of its own.  The runtime sysfs attributes will be removed.
// */
//void pm_runtime_no_callbacks(struct device *dev)
//{
//	spin_lock_irq(&dev->power.lock);
//	dev->power.no_callbacks = 1;
//	spin_unlock_irq(&dev->power.lock);
//	if (device_is_registered(dev))
//		rpm_sysfs_remove(dev);
//}
//EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);

///**
// * pm_runtime_irq_safe - Leave interrupts disabled during callbacks.
// * @dev: Device to handle
// *
// * Set the power.irq_safe flag, which tells the PM core that the
// * ->runtime_suspend() and ->runtime_resume() callbacks for this device should
// * always be invoked with the spinlock held and interrupts disabled.  It also
// * causes the parent's usage counter to be permanently incremented, preventing
// * the parent from runtime suspending -- otherwise an irq-safe child might have
// * to wait for a non-irq-safe parent.
// */
//void pm_runtime_irq_safe(struct device *dev)
//{
//	if (dev->parent)
//		pm_runtime_get_sync(dev->parent);
//	spin_lock_irq(&dev->power.lock);
//	dev->power.irq_safe = 1;
//	spin_unlock_irq(&dev->power.lock);
//}
//EXPORT_SYMBOL_GPL(pm_runtime_irq_safe);

///**
// * update_autosuspend - Handle a change to a device's autosuspend settings.
// * @dev: Device to handle.
// * @old_delay: The former autosuspend_delay value.
// * @old_use: The former use_autosuspend value.
// *
// * Prevent runtime suspend if the new delay is negative and use_autosuspend is
// * set; otherwise allow it.  Send an idle notification if suspends are allowed.
// *
// * This function must be called under dev->power.lock with interrupts disabled.
// */
//static void update_autosuspend(struct device *dev, int old_delay, int old_use)
//{
//	int delay = dev->power.autosuspend_delay;

//	/* Should runtime suspend be prevented now? */
//	if (dev->power.use_autosuspend && delay < 0) {

//		/* If it used to be allowed then prevent it. */
//		if (!old_use || old_delay >= 0) {
//			atomic_inc(&dev->power.usage_count);
//			rpm_resume(dev, 0);
//		} else {
//			trace_rpm_usage_rcuidle(dev, 0);
//		}
//	}

//	/* Runtime suspend should be allowed now. */
//	else {

//		/* If it used to be prevented then allow it. */
//		if (old_use && old_delay < 0)
//			atomic_dec(&dev->power.usage_count);

//		/* Maybe we can autosuspend now. */
//		rpm_idle(dev, RPM_AUTO);
//	}
//}

///**
// * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
// * @dev: Device to handle.
// * @delay: Value of the new delay in milliseconds.
// *
// * Set the device's power.autosuspend_delay value.  If it changes to negative
// * and the power.use_autosuspend flag is set, prevent runtime suspends.  If it
// * changes the other way, allow runtime suspends.
// */
//void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
//{
//	int old_delay, old_use;

//	spin_lock_irq(&dev->power.lock);
//	old_delay = dev->power.autosuspend_delay;
//	old_use = dev->power.use_autosuspend;
//	dev->power.autosuspend_delay = delay;
//	update_autosuspend(dev, old_delay, old_use);
//	spin_unlock_irq(&dev->power.lock);
//}
//EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);

///**
// * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
// * @dev: Device to handle.
// * @use: New value for use_autosuspend.
// *
// * Set the device's power.use_autosuspend flag, and allow or prevent runtime
// * suspends as needed.
// */
//void __pm_runtime_use_autosuspend(struct device *dev, bool use)
//{
//	int old_delay, old_use;

//	spin_lock_irq(&dev->power.lock);
//	old_delay = dev->power.autosuspend_delay;
//	old_use = dev->power.use_autosuspend;
//	dev->power.use_autosuspend = use;
//	update_autosuspend(dev, old_delay, old_use);
//	spin_unlock_irq(&dev->power.lock);
//}
//EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);

/**
 * pm_runtime_init - Initialize runtime PM fields in given device object.
 * @dev: Device object to initialize.
 */
void pm_runtime_init(struct device *dev)
{
//	dev->power.runtime_status = RPM_SUSPENDED;
//	dev->power.idle_notification = false;

//	dev->power.disable_depth = 1;
//	atomic_set(&dev->power.usage_count, 0);

//	dev->power.runtime_error = 0;

//	atomic_set(&dev->power.child_count, 0);
//	pm_suspend_ignore_children(dev, false);
//	dev->power.runtime_auto = true;

//	dev->power.request_pending = false;
//	dev->power.request = RPM_REQ_NONE;
//	dev->power.deferred_resume = false;
//	dev->power.needs_force_resume = 0;
//	INIT_WORK(&dev->power.work, pm_runtime_work);

//	dev->power.timer_expires = 0;
//	hrtimer_init(&dev->power.suspend_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
//	dev->power.suspend_timer.function = pm_suspend_timer_fn;

//	init_waitqueue_head(&dev->power.wait_queue);
}

/**
 * pm_runtime_reinit - Re-initialize runtime PM fields in given device object.
 * @dev: Device object to re-initialize.
 */
void pm_runtime_reinit(struct device *dev)
{
//	if (!pm_runtime_enabled(dev)) {
//		if (dev->power.runtime_status == RPM_ACTIVE)
//			pm_runtime_set_suspended(dev);
//		if (dev->power.irq_safe) {
//			spin_lock_irq(&dev->power.lock);
//			dev->power.irq_safe = 0;
//			spin_unlock_irq(&dev->power.lock);
//			if (dev->parent)
//				pm_runtime_put(dev->parent);
//		}
//	}
}

/**
 * pm_runtime_remove - Prepare for removing a device from device hierarchy.
 * @dev: Device object being removed from device hierarchy.
 */
void pm_runtime_remove(struct device *dev)
{
//	__pm_runtime_disable(dev, false);
//	pm_runtime_reinit(dev);
}

/**
 * pm_runtime_get_suppliers - Resume and reference-count supplier devices.
 * @dev: Consumer device.
 */
void pm_runtime_get_suppliers(struct device *dev)
{
//	struct device_link *link;
//	int idx;

//	idx = device_links_read_lock();

//	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
//				device_links_read_lock_held())
//		if (link->flags & DL_FLAG_PM_RUNTIME) {
//			link->supplier_preactivated = true;
//			pm_runtime_get_sync(link->supplier);
//			refcount_inc(&link->rpm_active);
//		}

//	device_links_read_unlock(idx);
}

/**
 * pm_runtime_put_suppliers - Drop references to supplier devices.
 * @dev: Consumer device.
 */
void pm_runtime_put_suppliers(struct device *dev)
{
//	struct device_link *link;
//	unsigned long flags;
//	bool put;
//	int idx;

//	idx = device_links_read_lock();

//	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
//				device_links_read_lock_held())
//		if (link->supplier_preactivated) {
//			link->supplier_preactivated = false;
//			spin_lock_irqsave(&dev->power.lock, flags);
//			put = pm_runtime_status_suspended(dev) &&
//			      refcount_dec_not_one(&link->rpm_active);
//			spin_unlock_irqrestore(&dev->power.lock, flags);
//			if (put)
//				pm_runtime_put(link->supplier);
//		}

//	device_links_read_unlock(idx);
}

//void pm_runtime_new_link(struct device *dev)
//{
//	spin_lock_irq(&dev->power.lock);
//	dev->power.links_count++;
//	spin_unlock_irq(&dev->power.lock);
//}

//static void pm_runtime_drop_link_count(struct device *dev)
//{
//	spin_lock_irq(&dev->power.lock);
//	WARN_ON(dev->power.links_count == 0);
//	dev->power.links_count--;
//	spin_unlock_irq(&dev->power.lock);
//}

///**
// * pm_runtime_drop_link - Prepare for device link removal.
// * @link: Device link going away.
// *
// * Drop the link count of the consumer end of @link and decrement the supplier
// * device's runtime PM usage counter as many times as needed to drop all of the
// * PM runtime reference to it from the consumer.
// */
//void pm_runtime_drop_link(struct device_link *link)
//{
//	if (!(link->flags & DL_FLAG_PM_RUNTIME))
//		return;

//	pm_runtime_drop_link_count(link->consumer);

//	while (refcount_dec_not_one(&link->rpm_active))
//		pm_runtime_put(link->supplier);
//}

//static bool pm_runtime_need_not_resume(struct device *dev)
//{
//	return atomic_read(&dev->power.usage_count) <= 1 &&
//		(atomic_read(&dev->power.child_count) == 0 ||
//		 dev->power.ignore_children);
//}

///**
// * pm_runtime_force_suspend - Force a device into suspend state if needed.
// * @dev: Device to suspend.
// *
// * Disable runtime PM so we safely can check the device's runtime PM status and
// * if it is active, invoke its ->runtime_suspend callback to suspend it and
// * change its runtime PM status field to RPM_SUSPENDED.  Also, if the device's
// * usage and children counters don't indicate that the device was in use before
// * the system-wide transition under way, decrement its parent's children counter
// * (if there is a parent).  Keep runtime PM disabled to preserve the state
// * unless we encounter errors.
// *
// * Typically this function may be invoked from a system suspend callback to make
// * sure the device is put into low power state and it should only be used during
// * system-wide PM transitions to sleep states.  It assumes that the analogous
// * pm_runtime_force_resume() will be used to resume the device.
// */
//int pm_runtime_force_suspend(struct device *dev)
//{
//	int (*callback)(struct device *);
//	int ret;

//	pm_runtime_disable(dev);
//	if (pm_runtime_status_suspended(dev))
//		return 0;

//	callback = RPM_GET_CALLBACK(dev, runtime_suspend);

//	ret = callback ? callback(dev) : 0;
//	if (ret)
//		goto err;

//	/*
//	 * If the device can stay in suspend after the system-wide transition
//	 * to the working state that will follow, drop the children counter of
//	 * its parent, but set its status to RPM_SUSPENDED anyway in case this
//	 * function will be called again for it in the meantime.
//	 */
//	if (pm_runtime_need_not_resume(dev)) {
//		pm_runtime_set_suspended(dev);
//	} else {
//		__update_runtime_status(dev, RPM_SUSPENDED);
//		dev->power.needs_force_resume = 1;
//	}

//	return 0;

//err:
//	pm_runtime_enable(dev);
//	return ret;
//}
//EXPORT_SYMBOL_GPL(pm_runtime_force_suspend);

///**
// * pm_runtime_force_resume - Force a device into resume state if needed.
// * @dev: Device to resume.
// *
// * Prior invoking this function we expect the user to have brought the device
// * into low power state by a call to pm_runtime_force_suspend(). Here we reverse
// * those actions and bring the device into full power, if it is expected to be
// * used on system resume.  In the other case, we defer the resume to be managed
// * via runtime PM.
// *
// * Typically this function may be invoked from a system resume callback.
// */
//int pm_runtime_force_resume(struct device *dev)
//{
//	int (*callback)(struct device *);
//	int ret = 0;

//	if (!pm_runtime_status_suspended(dev) || !dev->power.needs_force_resume)
//		goto out;

//	/*
//	 * The value of the parent's children counter is correct already, so
//	 * just update the status of the device.
//	 */
//	__update_runtime_status(dev, RPM_ACTIVE);

//	callback = RPM_GET_CALLBACK(dev, runtime_resume);

//	ret = callback ? callback(dev) : 0;
//	if (ret) {
//		pm_runtime_set_suspended(dev);
//		goto out;
//	}

//	pm_runtime_mark_last_busy(dev);
//out:
//	dev->power.needs_force_resume = 0;
//	pm_runtime_enable(dev);
//	return ret;
//}
//EXPORT_SYMBOL_GPL(pm_runtime_force_resume);
